Speed-governing apparatus for injection internal combustion engines



Aug. 24, 1937. "A. SCHWEIZER 2,091,163

SPEED GOVERNING APPARATUS INJECTION INTERNAL COMBUSTION ENGINES Filed April 1, 1936 Patent ed Aug. 24, 1937 UNITED STATES PATENT OFFICE JECTION GINES INTERNAL COIVIBUSTION EN- Alfred Schweizer, Stuttgart, Germany, asslgnor to Robert Bosch Aktie Germany ngesellschait, Stuttgart,

Application April 1, 1936, Serial No. 72,159

In Germany April 11, 1935 v 11 Claims. (Cl. 1 23 103) The invention relates to a speed-governing apparatus for injection internal combustion engines, of the type wherein the injection amount is controlled by a pneumatic governor operated by the pressure in an air-supply pipe, in which a voluntarily adjustable throttlemember isprovided.

This type of governor fails to operate when the Such a reversal may occur, for instance, when w owing to unskilled handling ofa vehicle on a steep ascent, the vehicle begins to run backwards and compelsthe vehicle engine to run in reverse; the engine then induces from the exhaust-pipe and forces the cylinder charge into the air-supply pipe, and accordingly the governor when the throttle-valve is closed no longer governs for idle running, for the reason that the vacuum or atmospheric pressure of the discharged cylinder charge no longer prevails at the point of junction of the branch pipe with the air-supply pipe. As a result thegovernor thus permits of a supply of fuel for running under full load in spite of the closed throttle valve.

This drawback can be removed according to the invention, by the control-chamber of the pneumatic governor being connected to a by-:

vention are shown in the accompanying drawing, in which:- 7

Figure 1 shows diagrammatically one'construction,

Figure 2 shows a second construction, and

Figure 3 shows a third construction.

In Figure 1, i is the casing of a fuel injection pump of known construction, having a camshaft 2 and pump pistons 3, which are rotated about their axis by a toothed rack-bar 4, and according to the degree of this angular movement, candelivermore or less fuel into the cylinders of the internal combustion engine to be governed. The rack-bar 4 can be adjusted by a piston 5 of a pneumatic governor, the cylinder of which is connected at one side by a pipe IS with the induction pipe 8 of the engineand at the other side by an opening I with the atmosphere.

The passagethroughthe induction pipe can be regulated by a throttle valve 9, the position of which is adjustable from a pedal lever l2through a lever l and connecting rod II. The throttlevalve is disposed in. a throat or Venturi tube I3 fixed in the induction pipe 8. By virtue of a longitudinal passage [4 and two transverse passages Md and Nb a by-pass is provided round the throat in the induction pipe controlled by the throttle 9. This by-pass is of such crosssectional area," that even with the throttle fully closed, the maximum amount of air capable of passing therethrough is that which enables idle running of the engine. In the longitudinal passage of this by-pass is located a symmetrical throat orVenturi tube vl5, whilst the pipe I6 leading to the casing of the pneumatic governor communicates with said throat centrally thereof. The arrangement works in such a way that on the ordinary direction of rotation of the en gine, air issucked through the induction pipe 8 in the direction indicated by the arrow A. In theposition of the throttle shown, air is sucked through the by-pass in the direction Ila, H, Nb, and .bythe venturi l suflicient vacuum is produced at the end of the pipe [6 to be able to operate the pneumatic governor. More air than.

is necessary for idle running must not pass through this side-branch, as otherwise the engine could no longer be adjusted for idle running merely by closing the throttle.

Ii for any reason the engine reversed its directionof rotation, the cylinder charge is forced through the induction pipe in the direction of the arrow B, and accordingly, as the driver wishes to stop and therefore has closed the throttle, the air stream in the by-pass pipe goes the reverse way in the direction Mb, I 4, Hay inthis case,

,the venturi 15 gives the vacuum again necessary to enable the governor to be operated in opposition to the backward running force by reducing' the amount of fuel injected. The possibility Venturi tube l3, one point being situated before. and the other behind, the throttle-valve 9. The action is the same as in the arrangement shown in Fig. 1.

In the construction shown in Fig. 3, the air induction pipe is duplicated, each half, 8a and 8b respectively, supplying the air for half the number of the cylinders; two throttle-valves 8a and 9b, acting in the same direction and thus coupled together, must, of course, then be provided. In this case, the by-pass pipe may be connected up behind the throttle-valve 9a and in advance of the throttle-valve 9b, and contain the symmetrical venturi l5 and the pipe [6 leading to the pneumatic governor. The operation in this arrangement is of course the same as in the previous two examples.

I declare that what I claim is:

1. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a throttle member in said conduit, means for voluntarily adjusting said throttle, a pneumatic governor operated by the pressure in said conduit and controlling the supply of, fuel to said engine and a by-pass in said air supply conduit extending to opposite sides of said throttle and in communication with said governor, said by-pass being so proportioned that with the throttle member closed the maximum volume of air capable of passing through the by-pass is that volume enabling idle running only of the engine.

2. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a throat therein, a voluntarily adjusted throttle valve in said throat, a pneumatic governor operated by the pressure in said conduit and controlling the supply of fuel to said engine and a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said governor, said by-pass being proportioned so that with the throttle valve closed the maximum volume of air capable of passing therethrough is that volume enabling idle running only of the engine.

3. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a Venturi constriction in said conduit, a throttle valve in said constriction, means for voluntarily adjusting the position of said valve, a pneumatic governor, a pipe connection between said governor and said air supply conduit and a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said pipe connection with said governor, said by-pass being proportioned so that with the throttle valve closed the maximum volume of air capable of passing therethrough is that volume enabling idle running only of the engine.

4. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, 2. Venturi constriction in said conduit, a throttle valve in said constriction, means for voluntarily adjusting the position of said valve, a pneumatic governor, a pipe connection between said governor and said air supply conduit and a by-pass in said air supply conduit both ends of which merge into the conduit in the narrow part of said throat on opposite sides of said valve when closed and which, intermediate its ends, is in communication with said pipe connection with said governor, said by-pass being proportioned so that with the throttle valve closed the maximum volume of air capable of passing therethrough is that volume enabling idle running only of the engine.

5. A speed governing apparatus for injection internal combustion engines comprising an air supply conduit, a Venturi constriction in said conduit, a throttle valve in said constriction, means for voluntarily adjusting the position of said valve, a pneumatic governor, a pipe connection between said governor and said air supply conduit, a by-pass in said air supply conduit both ends of which merge into the conduit in the narrow part of said throat on opposite sides of said valve when closed and which, intermecliate its ends, is in communication with said pipe connection with said governor, said by-pass being proportioned so that with the throttle valve closed the maximum. volume of air capable of passing theretl rough is that volume enabling idle running only of. the engine and a Venturi constriction in said by-pass in the region of the connection with said pipe connection to said governor.

6 A speed governing apparatus .for injection internal combustion engines comprising an air supply conduit, a Venturiconstruction element in said conduit, a throttle valve in said constriction, means for voluntarily adjusting the position of said throttle valve, a pneumatic governor, a by-pass in said conduit extending to opposite sides of said throttle valve when closed and housed wholly within said Venturi constriction element, the cross sectional area of said by-pass being such that the maximum volume of air passing therethrough is at most the amount of air required for idle running only of the engine and a pipe connection between said governor and said by-pass.

'7. A speed governing apparatus for injection internal combustion engines comprising two air supply conduits, throats in said conduits, throttle valves in said throats, means common to all of said valves for adjusting their position within said throats, a pneumatic governor and pipe means between said governor and said throats, said pipe means being connected to the space behind the throttle valve in one conduit and to the space before the throttle valve in the other conduit.

8. A speed governing apparatus for injection internal combustion engines comprising two air supply conduits, throats in said conduits, throttle valves in said throats, means common to all of said valves for adjusting their position within said throats, a pneumatic governor and pipe means between said pneumatic governor and said throats, said pipe means including a Vcnturi constriction and being connected to the space behind the throttle valve in one conduit and to the space before the throttle valve in the other conduit.

9. A speed governing apparatus for injection internal combustion engines comprising an air supplying conduit, a voluntary adjusted throttle valve, a pneumatic governor operated by the pressure in said conduit and controlling the supply of fuel to said engine, a by-pass in said air supply conduit extending to opposite sides of said throttle valve when closed and in communication with said governor, said by-pass being proper tioncd so that with the throttle valve closed the maximum volume of air capable of passing there through is that volume enabling idle running only of the engine, and a Venturi constriction in running from the space behind the throttle in the one conduit to the space before the throttle in the other conduit, a pneumatic governor controlling the supphr of fuel to said engine, and pipe means between said governor and the throat in said connection.

11. A speed governing apparatus for injection internal combustion engines comprising a .pair

0! air supply conduits, throttle valves in said conduits, means common to said valves for adjusting their position within said conduits, a throat-containing connection runing from the space behind the throttle valve in one conduit to the space before the throttle valve in the other conduit, a pneumatic governor controlling the supply of fuel to said engine, and pipe means between the governor and the throat in said connection, said connection being proportioned so that with the throttle valves closed the maximum volume of air capable of passing. therethrough is that volume enabling idle running only of the engine.

ALFRED SCHWEIZER. 

